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Not too surprisingly, the GEM RP-X tests much like the GEM pRP-800 that I reviewed previously ... so you might want to check that out as well. The main voice here is different than the Steinway or Fazioli however. I'm not sure how one would characterize it (in terms of what brand of physical piano it was sampled from) but I didn't find any technical match in terms of phase signatures and such between this and either of the pRP-800 pianos voices I tested.

I checked into this with someone who use to work for GEM.

Piano 1 was indeed the Fazioli. (Maybe I should have sent PIano 2 as well, the Steinway... I might be able to get you that in the future, if you'd like to see it.) The rep explained your noted inconsistency this way:

"The pRP700/800 and the RP-X share the same reference sample data and physical modeling. Where the difference lies is in the post-EQ. The pRP800 has internal speakers and the EQ is set to enhance that speaker system. There are two EQ setting that are user switchable for use with the internal speakers or for external amplification. The pRP700 also has an equalizer at the end of the audio chain. Throughout production changes were being made to the EQ settings of the pRP700/800 as per customer input. The RP-X has a five band EQ as well which is user adjustable. My guess is that the units tested had varying EQ settings and effects settings which would correlate to discrepancies of the spectral analysis."

Originally Posted By: dewster

Instead of velocity layers, GEM says they use something called "FADE" to alter timbre with velocity. From the description it sounds like a single layer sample with a filter (not sure how complex) and a velocity / time tracking look-up table. It is listed under the heading of physical modeling, but I'm not sure it quite qualifies in my mind as such. For example, Yamaha has a single layer sample with filter too and they don't call it modeling.

I'm not convinced the Yamaha p95 is single layer, as I hear a definite timbral shift at one point, much more abrupt than what would expect simply a velocity-based filter algorithm, which would tend to create a more gradual shift. I'll try to get you a recording of that at some point. But more to this particular issue, here is how GEM's approach qualifies as modeling, according to their manual:

"Unlike the velocity-switching methods used in other electronic pianos, Generalmusic’s unique FADE technology utilizes only one specially configured sound source per note." So yes, it is single layer. they continue:

"At the heart of the FADE engine is a extensive database which can be used to lookup the precise harmonic content of any note played at any velocity level. Whenever a note is played, the FADE engine analyzes the velocity of the key-strike and constructs, in real-time, a model of the necessary harmonic content for that particular note played at that velocity. The note’s sound source is processed by the FADE engine with appropriate harmonic content being added or subtracted accordingly." So it doesn't seem to be using a filter at all. The alterations to the harmonic content appears to be entirely based on a look-up table... that's the modeling, and that's different from using a filter, even if both are based on a single layer. I mean, for dynamic timbral changes to a note based on velocity, I think that using a look-up table to generate the harmonic content as opposed to just opening or closing a filter is pretty much the definition of a modeled approach, no?

Other than that, as you point out, they use modeling for key-down string resonance, pedal-down string resonance, and probably the key release string dampening.

"The pRP700/800 and the RP-X share the same reference sample data and physical modeling. Where the difference lies is in the post-EQ. The pRP800 has internal speakers and the EQ is set to enhance that speaker system. There are two EQ setting that are user switchable for use with the internal speakers or for external amplification. The pRP700 also has an equalizer at the end of the audio chain. Throughout production changes were being made to the EQ settings of the pRP700/800 as per customer input. The RP-X has a five band EQ as well which is user adjustable. My guess is that the units tested had varying EQ settings and effects settings which would correlate to discrepancies of the spectral analysis."

Thanks! I've only had limited opportunity with identifying sample sets that have had EQ applied. I certainly haven't had enough experience to definitively say two sets aren't the same when there is no spectral match, but when there is a strong match I feel pretty comfortable saying they are the same.

Originally Posted By: anotherscott

I'm not convinced the Yamaha p95 is single layer, as I hear a definite timbral shift at one point, much more abrupt than what would expect simply a velocity-based filter algorithm, which would tend to create a more gradual shift. I'll try to get you a recording of that at some point.

Is this timbre shift audible to you in the DPBSD MP3 layer test for the P95? If not, perhaps this shift is more obvious on a note other than middle C? I could easily provide a MIDI file with the layer test targeting one or more different notes. Let me know, I would certainly be interested in analyzing this issue.

Originally Posted By: anotherscott

But more to this particular issue, here is how GEM's approach qualifies as modeling, according to their manual:

"Unlike the velocity-switching methods used in other electronic pianos, Generalmusic’s unique FADE technology utilizes only one specially configured sound source per note." So yes, it is single layer. they continue:

"At the heart of the FADE engine is a extensive database which can be used to lookup the precise harmonic content of any note played at any velocity level. Whenever a note is played, the FADE engine analyzes the velocity of the key-strike and constructs, in real-time, a model of the necessary harmonic content for that particular note played at that velocity. The note’s sound source is processed by the FADE engine with appropriate harmonic content being added or subtracted accordingly." So it doesn't seem to be using a filter at all. The alterations to the harmonic content appears to be entirely based on a look-up table... that's the modeling, and that's different from using a filter, even if both are based on a single layer. I mean, for dynamic timbral changes to a note based on velocity, I think that using a look-up table to generate the harmonic content as opposed to just opening or closing a filter is pretty much the definition of a modeled approach, no?

I think we're arguing semantics more than anything else here. Their process probably doesn't create harmonic content, otherwise it wouldn't require a sample as input. From their description it alters the harmonic content of a sample fed through it - which to me is a filter because that's what filters do. Filters can be simple or complex, and can certainly be controlled via computed look-up tables.

So when I say "filter" I don't necessarily mean a simple low pass 12/24 dB roll off filter like in a Moog. It could be that simple in the P95, but probably not in the GEM.

In the GEM I imagine the single piano sample is routed through a multi-band (FFT based with linear binning?) filter. A series of timed look-up tables set the gains for these frequency bands, with linear interpolation between successive table entries (per band). That's a guess - it could be something even simpler but probably not more complex. Depending on the width of the bands, a sound could be radically altered this way.

Since it is excited by a piano note rather than white noise (i.e. we aren't trying to make a piano note out of whole cloth, just alter it some) the bands can be quite a bit wider and fewer - and so there is strong inherent data compression to this approach. Which made a lot of sense when ROM was small and computers were slow and both were expensive. These days not so much, though I do see the merits of modeling for performance inputs that affect the piano model itself (e.g. pedal and key sympathetic resonance).

Thanks to Piano World forum member "anotherscott" we have two DPBSD samples of the Korg Kronos - thanks! These samples are of the "German D" and "Japanese C" stock SGX-1 Premium Piano voices in the Kronos. In the Kronos literature Korg claims "Each uses superb, unlooped stereo samples, sampled at eight velocity levels for each and every key." - which certainly sounds like what many of us have been waiting for!

Though perhaps in a smaller, lighter, more piano-centric package. I see Korg neglected to include support for a music rest and decided to put the joystick in the keyboard area (both of which are Roland's wont). This seems to be the norm for a "workstation" class product, but I see these design decisions as rather unfortunate. Also, I'm not a huge fan of slide pots, or pots in general as digital input, because the physical position generally has no meaning once the patch is changed, and how position resynching is accomplished is invariably cumbersome - give me digital rotary encoders and dedicated LED displays instead.

Maybe my expectations were too high... 4.7 gb, no loops, no stretching... but while not a terrible piano by any means, I actually found the Kronos piano to be disappointing. I've only played with the two main voices, not all the variations, but based on those, I found the attack too severe relative to a very steep drop-off, especially when playing at high velocity. It can sound plunky. If you hit a right hand chord and hold it while continuing to play a moving left hand line underneath, it may not be long before you can no longer make out the held notes. And even though there are no loops, I don't really hear the benefit of that, because the sustains still quickly fall into something very static, almost like the piano only has one string per key, an effect typical of a looped piano sample, but not something you experience on a real piano. It's true that you don't hear the "pulsing" typical of loops, but actually, that's something I always found hard to detect in actual playing anyway... it was the richness of a more harmonically complex "unloopable" sound I was hoping for, and I don't hear it here. Maybe the sampled piano was just tuned too perfectly? I realize different people are sensitive to different things... Dewster seems to be very sensitive to looping effects, so he would probably be more pleased with the Kronos than I am. But overall, between the hard attack and the thin sustain, I found the sound to be actually a bit reminiscent even of an old Yamaha CP-80. I do like the Kronos for many of its other features. But when I recently gigged with the Kronos and a Yamaha MOX8, I chose to use the MOX for my piano sound. At some point, though, I do want to play with some of the other Kronos variations and maybe some of the editing facilities and see what else it may be capable of. Unlike most DPs, the Kronos includes all the editing functionality you could desire, I think you could go so far as to "build" your own custom piano sound out of its raw samples, if you're so inclined. But at least playing the main sounds out of the box, while I could certainly gig with it, I find numerous other pianos more enjoyable to play. I should also mention that, while I had the 61 key Kronos, I evaluated the piano by triggering it from a weighted 88 key board.

Some pix:Figure 1. Spectral phase view of the pedal sympathetic resonance test, stimulus removed, normalized to -1dB to increase clarity, pedal down @ left, pedal up @ right, Japanese C. Because the effect is sampled, the sound is very realistic and pleasant.

Figure 2. Waveform view of the entire looping test, vertical zoom applied to see the noise floor, German D. Note decay is generally nice and long, though C1 on the German D poops out kind of early. The key-off "klunk" sound effect can be clearly seen here too (as well as heard, the default setting is much too loud).

Figure 4. Spectral pan view of the stretch test, mid notes, normalized to -1dB to increase clarity, German D. Here you can see what appears to be one stretch group of two on the left, and I believe there is another located in the higher end (not shown here). They don' jump out at me audibly, I don't think I would notice either without these visual cues. I don't see / hear any stretch groups with the Japanese C.

Figure 5. Spectral pan view of the layer test, compressed 20:1 to bring out detail, Japanese C. Visual evidence for at least seven layers (Korg says 8) with somewhat audible layer transitions. The most audible layer transition is the loudest one on the right, which sounds kind of tacked-on to me. The lowest velocity layer sounds somehow blended to me.

I'm very happy with my CP50, especially the keyboard wich is very dynamic and noiseless (not like my last HP307) but a bit heavy. I'm very happy too with the electric pianos (particulary the DX sounds !). I feel the piano sound not so deep than Pianoteq or Garritan Steinway but the Yamaha sound is for me really pleasant.

Sympathetic resonance sounds OK in the first and second pedal resonance tests, but sounds really echoy in the half pedaling test. It could very well be the case that the short note loop time (0.5 seconds for the half-pedaling test note C4) is interacting with one or more of the delay times that comprises the pedal resonance effect.

The C5 note is kind of strange: the loop itself sounds somewhat thinner than the end of the attack, which makes the attack / loop crossfade fairly audible from a timbre standpoint.

I only see two velocity layer switches, and the lowest one is in a different location than on the CP1 and CP5. The CP1 and CP5 differ from each other in this respect as well. I probably don't have enough information to say difinitively, but it seems like Yamaha may be yanking layers with decreasing retail price of the models in this line, something I wasn't really expecting to find any evidence of:

Another explaination could be that they are just doing a better job of blending the layers on the less expensive DPs, but that strikes me as rather counter-intuitive.

A few (comparative) analysis pix (see the ZIP file for more):Figures 1A, 1B, 1C. Spectral pan view of the stretch test, mid notes, CP1 (top), CP5 (middle), CP50 (bottom). Amplitude normalized to -1dB to bring out detail. No significant visible or audible differences, stretch groups are the same in all three models. (The CP50 image is offset 4 notes due to the way I captured the image, the sample set itself is not offset compared to the CP1/5).

The audible stretch groups and velocity levels are quite apparent, and the lack of resonance and pedal features are also obvious. On the plus side, the length of the samples makes for quite a pleasant listening experience.

As a very lightweight stage piano, it does its job. I particularly like the Rhodes sample, and I find the AP adequate, if not scintillating. It is at least a very clear-sounding AP. Unfortunately, I haven't had much opportunity to play it yet, due to a damaged finger, so my thoughts are somewhat preliminary and subject to reevaluation in the future.

From a sound technology standpoint, the strong point of this DP is the looping, which (from my sub sample of 8 notes) seems to be pretty well done (as these things go). The attack samples are fairly long, the crossfades seem well blended, and most of the loops themselves are subtle sounding. I can hear looping in the midrange, but it isn't very prominent.

It has many weak points though. There is no sympathetic resonance of any kind, and most key / pedal interaction is not implemented. There are 5 velocity layers, but they are unblended, and the highest layer transition is rather jarring. With 36 stretch groups the sample set is fairly stretched, and some of the groups have left / right pan issues: several higher note stretch groups sound somewhat panned left, and one of the lower stretch groups sounds like it is panned right. It's probably just me, but issues with very basic things like L/R pan in the sample set leave me with a slight queasy feeling towards the entire implementation.

Many may not care for the white motif, but I really appreciate the location of the pitch and mod wheels (not in the keybed area), the inclusion of a music rest, the overall compactness, and the relative light weight of the physical design.

Figure 2. Waveform view of the entire looping test, vertical zoom applied to see the noise floor. Note decay is generally long, though the lowest notes could probably use more decay time.

Figure 3. Spectral pan view of the note C3, normalized to -1dB to increase clarity, cursor at end of crossfade. Fairly long attack and loop samples, with smooth crossfade. Looping sounds pretty well done.

Figure 4. Spectral phase view of the stretch test, mid notes, normalized to -1dB to increase clarity. High end is similar, low end is more stretched. Stretch group transitions are audible over the low and mid notes.

Figure 5. Waveform view of the entire stretch test (chromatic walk up the keyboard), left channel on top, right on bottom. Highlighted region indicates a lower stretch group with a right panning issue, you can also see indications of a left panning issue with some of the higher stretch groups.

Interesting. So the CP1 is according to these tests entirely ordinary and with the acoustic piano sound Yamaha breaks no new ground at all. On a subjective level though it seems to have been very well received. I'm very impressed with the few bits I've heard.

The test is not taking into account aspects of the CP1 AP that are modelled, for example hammer hardness. Also, the approach to dynamics is new (according to Yamaha) and the proof is in the playing. It has a remarkable range and smoothness. Play it, and you'll be left wondering what the fuss is about, in terms of the DP BSD results. Adjusting the hammers on this instrument is amazing, and transforms the pianos! (And that is only one aspect that has been modelled).

The DP BSD is not the be all and end all - especially for an instrument that combines samples and modeling. (And also, let's not forget that the interpretation of the test results is to a certain extent subjective - and being made by one individual).

I've spent enough hours to make at least a week playing the CP1 and V-Piano before deciding on the V-piano for purchase. I believe it is a conbination of the sound (quadraphonic setup) on the V-piano coupled with the keyboard being smoother to play. I own a CLP990 and got used to a heavier feel on the keys, however switching tho the V-piano has improved my playing, at least subconscioulsy..lol.. I was expecting more from the CP1 considering it has come out two years after the V-piano. However I prefer my CLP990 over it if I had to choose. The v-piano keeps calling for me to play it, so I made the choice to get one. For the last six months, I've been using a college owned V-piano, and yesterday I made the purchase for my home. Coupled with my CLP990 and an S90 from yamaha, I will have a new edition to my keyboard family. Thanks for the reviews on the actual sounds. Even though I don't hear a problem with the midrange on the V-piano as others have, it is good to have opinions and there is always room for improvement. One day one of these companies shall achieve perfection. At the moment the V-piano is still the closest thing to that as the CP1 falls short of expectations.

In a mere 9 months the DPBSD thread has doubled its views to reach the half million mark - thanks everyone for the continued interest, and thanks to Pianoworld for hosting this awesome forum! Have some cake (no Kit Kats this time, just pure creamy icing goodness)!

In a mere 9 months the DPBSD thread has doubled its views to reach the half million mark - thanks everyone for the continued interest, and thanks to Pianoworld for hosting this awesome forum! Have some cake (no Kit Kats this time, just pure creamy icing goodness)!

I would be very interested DPBSD MP3s of both (the default SuperNATURAL piano with all resonance and sound effects enabled - PM me if you need help doing this). I've read reports lately that the SN piano voice in the RD-300NX sounds inferior to that in the RD-700NX / RD-700GXF / FP-7F / HP307 and I'd like to get to the bottom of this if possible.

[EDIT] I could also use a DPBSD MP3 of the Yamaha CP1 S6 piano voice. And if you're feeling extra charitable, I could use an updated CP1 CF sample as well!

Anotherscott previously gave us DPBSD MP3s of the NP-V80: the default voice "Live! Grand Piano" and the third voice "Grand Piano". At that time I reviewed the main voice in the NP-V80, but decided not to review the third voice as it tested somewhat inferior to the main patch. The reason anotherscott provided it was due to his speculation at the time that it might be identical to the NP-V60 main piano voice.

After a quick listening comparison when able to subsequently directly compare the two, anotherscott felt the NP-V60 main voice and NP-V80 third voice indeed sounded quite similar, but he heard a difference in how the lower notes were stretched:

Originally Posted By: anotherscott

the version of the sound on the NP-V80 sounds like the lowest notes are stretched from a higher point. My guess is it might be the same sound, but to save ROM space since it wasn't the main piano on the NP-V80, they removed the samples that were outside the unit's own 76 note range? But that's just a guess. Still, what a terrible sound, though, that sustain... what there is of it...

Which I confirmed in my testing. Looking at the stretch test for both the V60 (main voice) and V80 (third voice) I'm seeing identical pan/phase signatures, the only exception being the V60 has one extra group located second to last from the bottom:

So both are super duper stretched, particularly on the ends, but the NP-V60 has one extra bass group.

Compared to the main NP-V80 piano voice, The NP-V60 piano voice tests worse in several critical ways: the decays are shorter, the attack and loop sample lengths are generally a lot shorter, and it's stretched more. This poor showing in comparison to an already fairly poor piano puts it firmly near the bottom of the DPs I've tested in terms of sound technology. The fast decays hide the short loops to some degree, but the decay rate itself sounds completely unrealistic. The extreme stretching of the lowest and highest ranges also sounds fake, and the stretch transitions are quite obviously audible. It's hard not to think of this voice as much more than one might find in a decent toy.

You would take that number and multiply it by the layers to get the total ROM required, if they are using filtering instead of actual layers the multiplier would then be 1. Any way that you look at this it's probably a really tiny, some would say microscopic, sample size. And while huge sample sets don't necessarily guarantee good sound, I would argue that tiny ones like this (particularly when compressed via stretching and looping) are always associated with poor sound.

Some analysis pix and text review:

Figure 1. Waveform view of the entire looping test, vertical zoom applied to see the noise floor. The decay rate is super fast.

Figure 3. Spectral pan view of the stretch test, low end of the notes, normalized to -1dB to increase clarity. Low and high ends are super stretched which makes the notes sound fake. Mids are fairly stretched, with mostly groups of 4. Stretch group transitions are quite audible over the entire range due to timbre and stereo pan mis-matches between stretch groups.

With its "61-note natural touch mini-keyboard" it may not be everyone's cup of tea, but those 5 octaves fit in a 778 x 210 x 82 mm (30.63" x 8.27" × 3.23") package that weighs only 2.6 Kg (5.73 lbs). At $500 USD this keyboard is both highly portable and affordable.

Some Q&A with anotherscott:

Originally Posted By: anotherscott

What do the small keys feel like to play and how controllable are they?

I find the Micro-keys surprisingly not bad. The size really didn't bother me much. I wouldn't attempt to practice stride piano on it, but for linear stuff, I adapted pretty easily. For an unweighted action, dynamic control is decent, and unlike many (most?) unweighted actions, the response is pretty consistent over most of the length of the key. That is, you can hit black keys toward the back of the key, and the response is about the same as at the front of the key. That's a typical failing of many unweighted boards which the Microstation manages to avoid. The keys have a nice positive feel to them. Of course, it's still not nearly as good for piano as a weighted action, but I'm looking at it on its own terms. And when using the action for non-weighted sounds, it's often actually feels quite good, I think. I'd be curious to know what it would feel like if they scaled this mechanism up to a full size key.

Do the piano decays sound short when you play it?

Yes, I do feel that it falls off to a lower level more quickly than I'd like (as numerous DPs do)... the subsequent sustain is decently long (though still shy of a real piano, certainly)... the very end of the sustain, where it quickly fades and cuts off, is very unnatural, but holding a note that long is pretty rare... and presumably no one is looking to perform a solo piano concert on a Microstation.

How about the timbre change with velocity? Do you think it's blended layers or a filter?

If I had to guess, I'd say one layer... because I can simulate the different timbres at the different velocities by turning the front panel filter cutoff, and it seems to match pretty well.

... just checked with the editor. Yup, one layer.

Kind of funny to see they used one layer for the acoustic piano, and then 3 for the rhodes...

Does the dynamic range seem too narrow?

Not to me.

Quality of the other voices?

Above average.... in fact, I find numerous other sounds stronger than their piano sound. Plus, since it really is a full workstation, the voices are extremely tweakable, much more than what you normally associate with DPs.

Ease of use (UI, PC editor, etc.)?

Depends where you're coming from. If you're coming from a DP perspective where you're expecting to see little more than 8 or 16 buttons labeled piano, EP, organ, strings, etc., it may at first seem a bit confusing... but if you've used any kind of rompler/workstation, it will probably be simpler than you expect. Really, it's not bad at all. Basic sound editing is pretty decent within the obvious constraints like a small 2-line screen. The computer editor is really quite nice. Again, probably a bit intimidating to someone who is used to nothing but patch selection buttons, but really, a lot of it is pretty intuitive if you have any sense about these kinds of things at all.

All in all, a serviceable piano sound and a whole lot of other stuff, in a very portable box that is fun to play. I think it's a great travel board, and really, just plain fun to have around. And if I had a gig and my main board went down, I definitely could manage to get through the gig on this as a spare.

Because the piano sample is mono, it's difficult for me to tell how long most of the attack and loop samples are. But as a very rough estimate let's say it's 1.8 seconds per stretch group.

1.8 sec/group * 16 groups * 48000 samples/sec * 2 B/sample = ~2.8 MB.

Which is 2.8 MB / 49 MB = ~1/17 of the ROM space. Since it shares this space with 359 other sample sets and a bunch of drums, the main piano sample consumes much more than its fair share (as is probably the case in most keyboards) but still it is much too tiny. I wish manufacturers would take the DP aspects of these kinds of products a bit more seriously, thought the synth stuff seems kind of neat if you watch the youtube videos.

Some analysis pix and text review:

Figure 1. Spectral pan view of the entire MP3. The main piano sample set is mono with some kind of mild stereo effect and appropriate L/R pan applied (note the 'S' shape of the sample stretching test on the right).

Figure 2. Waveform view of the looping test, zoomed vertically in order to see the noise floor (so that the decays have a clear visual reference). Decay times of the low and mid notes are too short. Attack samples sound fairly decent, looping isn't too terribly done though the loop sample lengths could be longer.

Figure 3. Waveform view of the entire stretch test (can't use the pan or phase views here due to mono). This sample set is really stretched, with a mere 16 samples covering 88 notes. Most stretch group transitions are audible.

Here's a blast from the DPBSD past - creaky old v1.2 as a matter of fact, performed over a year and a half ago at a point where I was still getting my analysis feet wet. It doesn't appear that I posted this previously, so here it is for historical purposes.

I tend to go on and on about the evils of looping. I have a personal loathing of it which I express perhaps too often in PW forum threads. PW member Brent_H recently described looping as "that uncanny effect where it sounds very like a piano for the first three quarters of a second and then exactly like someone turning down a volume knob as it decays." This is a very apt analogy because, with few exceptions, DP synthesis consists of exactly that.

Here is what most DPs do when you play a note:

1. They play back a few seconds of a recorded sample of the first part of the note - the attack sample. The bass notes are almost always allotted more sample time than the treble notes because it takes longer for bass notes to "settle down" into their decay phase.

2. This is followed by a short crossfade, which is a smooth transition that goes fully from one sound to another via simple mixing, over to:

3. a short piece of the recorded sample played over and over - the loop sample - with an envelope applied in order to form the dropping volume over time decay sound. The looped decay may be accompanied by a gradual introduction of a low pass filter, which dulls the highs over time.

Given a little thought, the problems with this approach should be immediately obvious. Piano note harmonic decay is much more complex than a simple reduction in volume and a dulling of the overall brightness. Often the loop sample period is audible because it isn't long enough to capture the "wobbling" sound of a string with multiple modes and one or more unison strings interbeating with it. So if you can hear the loop period it almost always sounds fake, but even if you can't it's still a real tone killer.

One of the technically best loopers I've tested in this thread is the Yamaha AvantGrand N3, which is also the most expensive DP I've tested. Let's look at some numbers from that review:

The AG has nice long attack (the crossfade time is included in the attack numbers) sample times. But it is hobbled by very short loops. In order to do this, Yamaha has to highly process the loops in order to remove any audible periodicity introduced by the looping itself, and in so doing they must remove long-term phase/pan changes due to the interbeating of unison strings, longitudinal modes, etc.

Many will tell you that looping doesn't matter much because it gets largely hidden during normal play. Indeed, this is the reason almost all demo songs in DPs consist of a flurry of quickly played short duration notes. They're intentionally emphasizing the positive by biasing the playback in favor of the most realistic sounding portion of each note, which is the attack sample. Bass notes that are held for any length of time are usually are accompanied by a bunch of higher notes playing, and it's hard not to interpret this as a conscious attempt to mask the sonic deficiencies of the looping bass notes.

The DPBSD test doesn't provide much opportunity to the listener who wants to hear what that particular DP sounds like in an actual performance. The pedal sympathetic resonance test plays several notes at once, but that's about it. So I decided to take the AG DPBSD MP3 file, which has all the C notes in it for the looping test, and perform a multi-channel mix. I arranged C1 (the lowest C on the piano) to start at time zero, then arranged C2 through C6 to have their attack-to-loop transitions aligned with that of C1. I then normalized it to -1dB peak, and applied a small amount of hiss reduction because the SNR of the source MP3 isn't the best. I played around with muting various combinations of the notes, but the worst loop sound I could come up with was that of the C1 all by itself, which sounds kind of like a motorboat.

For comparison, I took the Roland RD-700NX "Concert Grand" DPBSD MP3 file and did the same exact thing, and even though it wasn't necessary I applied the hiss reduction to keep the playing field as level as possible. In order to highlight the differences in the decays rather than the attacks, I took the period from 5 seconds to 10 seconds in each of these and put them at the end of the file For a more direct comparison.

Figure 1. Spectral pan view of a mix of the notes C1 through C6, all MIDI velocities 63, stacked so that all attack/loop transitions are aligned. 1st segment (from the left) is the Yamaha AvantGrand N3; 2nd segment is the Roland RD-700NX (no looping but identical timing of the notes); 3rd segment is the central 5 seconds of the 1st segment; 4th segment is the central 5 seconds of the 2nd segment. Both note mixes were independently normalized to -1dB, then a light hiss reduction was applied to push down the audible noise floor. Full transition to looping of all notes for the AG begins at 4.4 seconds into the file. All samples taken from the associated DPBSD MP3 test files.

- What I hear -What you see in the spectral pan view above is pretty much what you get. The NX decays have that slow random phasey thing going on like a real piano, the ensemble decay of many notes sounds rich and thick. The AG loops sound completely dead in comparison, and putting a bunch of them together doesn't seem to improve the sound significantly - granted this is stereo, but I can't imagine 4 channels of that improving things much either. To my ears the differences in the decays between looped and SN are like night and day.

- Disclaimer -We've owned the NX for over a year now but readers shouldn't interpret this post as a plug for it in any way. I'm only using it here to highlight the sonic deficiencies of one of the best and most expensive loopers on the market. The NX has a lot going for it, but once a fully sampled stage/slab DP hits the market with good keys, good sound, and good user interface, we'll most likely sell the NX and get that.

Something I didn't realize before an explanation of dewster, is that this pan view really mesure the "motion" of the frequencies in the stereo pan. So the decay is twice flawed :1) the decay is looped (in a sens of periodic / in time), so wrong "melody" of sound (artifical)2) the decay is static "physically" in stereo pan, so the harmonics are not rolling / moving around our ears, but are completely inert. so wrong "presence/motion" of sound (artificial).

Probably just an artifact from normalizing the amplitudes, which often messes with the noise floor. Or perhaps somehow injected during recording. I seriously doubt it exists in the AG source.

Originally Posted By: zack!

... this pan view really mesure the "motion" of the frequencies in the stereo pan. So the decay is twice flawed :1) the decay is looped (in a sens of periodic / in time), so wrong "melody" of sound (artifical)2) the decay is static "physically" in stereo pan, so the harmonics are not rolling / moving around our ears, but are completely inert. so wrong "presence/motion" of sound (artificial).

Yes, the various colored lines in the spectral pan view represent harmonics, and the vertical axis is left / right pan. So when the lines move vertically the harmonics are moving around in the stereo field. Lots of that going on with real pianos and with SN, none really with the AG.

1. With looping there is no complex evolution of the individual harmonic amplitudes themselves.

2. In something with loops as short as the AG, harmonic pan movement really isn't possible without audibly revealing the looping cycle. So they squash it by over processing the loops, but end up throwing the baby out with the bathwater.